README.md

React Native Tab View

A cross-platform Tab View component for React Native.

This is a JavaScript-only implementation of swipeable tab views. It's super customizable, allowing you to do things like coverflow.

• Run the example app to see it in action.
• Checkout the example/ folder for source code.

Features

• Smooth animations and gestures
• Scrollable tabs
• Supports both top and bottom tab bars
• Follows Material Design spec
• Highly customizable
• Fully typed with Flow

Demo

Installation

yarn add react-native-tab-view

Quick Start

import * as React from 'react';
import { View, StyleSheet, Dimensions } from 'react-native';
import { TabView, TabBar, SceneMap } from 'react-native-tab-view';

const FirstRoute = () => (
  <View style={[styles.container, { backgroundColor: '#ff4081' }]} />
);
const SecondRoute = () => (
  <View style={[styles.container, { backgroundColor: '#673ab7' }]} />
);

export default class TabViewExample extends React.Component {
  state = {
    index: 0,
    routes: [
      { key: 'first', title: 'First' },
      { key: 'second', title: 'Second' },
    ],
  };

  render() {
    return (
      <TabView
        navigationState={this.state}
        renderScene={SceneMap({
          first: FirstRoute,
          second: SecondRoute,
        })}
        onIndexChange={index => this.setState({ index })}
        initialLayout={{ width: Dimensions.get('window').width }}
      />
    );
  }
}

Integration with React Navigation

React Navigation integration can be achieved by the react-navigation-tabs package. Note that while it's easier to use, it is not as flexible as using the library directly.

Examples on Snack

• Quick Start
• Custom Tab Bar

API reference

The package exports a TabView component which is the one you'd use to render the tab view, a TabBar component which is the default tab bar implementation, as well as several pager components for more fine-grained control.

In a trivial app, you'd mostly only use TabView and TabBar.

<TabView />

Container component responsible for rendering and managing tabs.

Example

<TabView
  navigationState={this.state}
  onIndexChange={index => this.setState({ index })}
  renderScene={SceneMap({
    first: FirstRoute,
    second: SecondRoute,
  })}
/>

Props

• navigationState (required): the current navigation state, should contain a routes array containing the list of tabs, and an index property representing the current tab.
• onIndexChange (required): callback for when the current tab index changes, should update the navigation state.
• renderScene (required): callback which returns a React Element to use as the scene for a tab.
• renderTabBar: callback which returns a custom React Element to use as the tab bar.
• renderPager: callback which returns a custom React Element to handle swipe gesture and animation.
• canJumpToTab: callback which returns a boolean indicating whether jumping to the tab is allowed.
• initialLayout: object containing the initial height and width, can be passed to prevent the one frame delay in rendering.
• tabBarPosition: position of the tab bar, 'top' or 'bottom'. Defaults to 'top'.

Any other props are passed to the underlying pager.

<TabBar />

Material design themed tab bar. To pass props to the tab bar, you'd need to use the renderTabBar prop of TabView to render the TabBar and pass additional props.

Example

renderTabBar={props =>
  <TabBar
    {...props}
    indicatorStyle={{ backgroundColor: 'pink' }}
  />
}

Props

• getLabelText: callback which returns the label text to use for a tab. Defaults to uppercased route title.
• getAccessible: callback which returns a boolean to indicate whether to mark a tab as accessible. Defaults to true.
• getAccessibilityLabel: callback which returns an accessibility label for the tab. Defaults to route title.
• getTestID: callback which returns a test id for the tab.
• renderIcon: callback which returns a custom React Element to be used as a icon.
• renderLabel: callback which returns a custom React Element to be used as a label.
• renderIndicator: callback which returns a custom React Element to be used as a tab indicator.
• renderBadge: callback which returns a custom React Element to be used as a badge.
• onTabPress: callback invoked on tab press, useful for things like scroll to top.
• pressColor: color for material ripple (Android >= 5.0 only).
• pressOpacity: opacity for pressed tab (iOS and Android < 5.0 only).
• scrollEnabled: whether to enable scrollable tabs.
• bounces: whether the tab bar bounces when scrolling.
• useNativeDriver: whether to use native animations.
• tabStyle: style object for the individual tabs in the tab bar.
• indicatorStyle: style object for the active indicator.
• labelStyle: style object for the tab item label.
• style: style object for the tab bar.

<PagerPan />

Cross-platform pager based on the PanResponder.

Props

• animationEnabled: whether to enable page change animation.
• swipeEnabled: whether to enable swipe gestures.
• swipeDistanceThreshold: minimum swipe distance to trigger page switch.
• swipeVelocityThreshold: minimum swipe velocity to trigger page switch.
• onSwipeStart: optional callback when a swipe gesture starts.
• onSwipeEnd: optional callback when a swipe gesture ends.
• onAnimationEnd: optional callback when the transition animation ends.
• getTestID: optional callback which receives the current scene and returns a test id for the tab.
• children: React Element(s) to render.

<PagerScroll />

Cross-platform pager based on ScrollView (default on iOS).

Props

• animationEnabled: whether to enable page change animation.
• swipeEnabled: whether to enable swipe gestures.
• onSwipeStart: optional callback when a swipe gesture starts.
• onSwipeEnd: optional callback when a swipe gesture ends.
• onAnimationEnd: optional callback when the transition animation ends.
• getTestID: optional callback which receives the current scene and returns a test id for the tab.
• children: React Element(s) to render.

There are some caveats when using this pager on Android, such as poor support for intial index other than 0 and weird animation curves.

<PagerAndroid />

Android only pager based on ViewPagerAndroid (default on Android).

Props

• animationEnabled: whether to enable page change animation.
• swipeEnabled: whether to enable swipe gestures.
• onSwipeStart: optional callback when a swipe gesture starts.
• onSwipeEnd: optional callback when a swipe gesture ends.
• onAnimationEnd: optional callback when the transition animation ends.
• keyboardDismissMode: whether the keyboard gets dismissed in response to a drag in ViewPagerAndroid (Default: on-drag).
• getTestID: optional callback which receives the current scene and returns a test id for the tab.
• children: React Element(s) to render.

<PagerExperimental />

Cross-platform pager component based on react-native-gesture-handler.

Props

• GestureHandler: the gesture handler module to use.
• animationEnabled: whether to enable page change animation.
• swipeEnabled: whether to enable swipe gestures.
• onSwipeStart: optional callback when a swipe gesture starts.
• onSwipeEnd: optional callback when a swipe gesture ends.
• onAnimationEnd: optional callback when the transition animation ends.
• useNativeDriver: whether to use native animations.
• getTestID: optional callback which receives the current scene and returns a test id for the tab.
• children: React Element(s) to render.

This pager is still experimental. To use this pager, you'll need to link the react-native-gesture-handler library, and pass it as a prop to the pager:

import * as GestureHandler from 'react-native-gesture-handler';

...

<PagerExperimental {...props} GestureHandler={GestureHandler} />

SceneMap

Helper function which takes an object with the mapping of route.key to React components and returns a function to use with renderScene prop.

renderScene = SceneMap({
  first: FirstRoute,
  second: SecondRoute,
});

Each scene receives the following props:

• route: the current route rendered by the component
• jumpTo: method to jump to other tabs, takes a route.key as it's argument

All the scenes rendered with SceneMap are optimized using React.PureComponent and don't re-render when parent's props or states change. If you don't want this behaviour, or want to pass additional props to your scene components, use renderScene directly instead of using SceneMap.

renderScene = ({ route }) => {
  switch (route.key) {
  case 'first':
    return <FirstRoute />;
  case 'second':
    return <SecondRoute />;
  default:
    return null;
  }

If you don't use SceneMap, you will need to take care of optimizing the individual scenes.

Optimization Tips

Use native driver

Using native animations and gestures can greatly improve the performance. To use native animations and gestures, you will need to use PagerExperimental as your pager and pass useNativeDriver in TabView.

<TabView
  navigationState={this.state}
  renderPager={this._renderPager}
  renderScene={this._renderScene}
  renderTabBar={this._renderTabBar}
  onIndexChange={this._handleIndexChange}
  useNativeDriver
/>

NOTE: Native animations are supported only for properties such as opacity and translation. If you are using a custom tab bar or indicator, you need to make sure that you animate only these style properties.

Avoid unnecessary re-renders

The renderScene function is called every time the index changes. If your renderScene function is expensive, it's good idea move each route to a separate component if they don't depend on the index, and apply shouldComponentUpdate to prevent unnecessary re-renders.

For example, instead of:

renderScene = ({ route }) => {
  switch (route.key) {
    case 'home':
      return (
        <View style={styles.page}>
          <Avatar />
          <NewsFeed />
        </View>
      );
    default:
      return null;
  }
};

Do the following:

renderScene = ({ route }) => {
  switch (route.key) {
    case 'home':
      return <HomeComponent />;
    default:
      return null;
  }
};

Where <HomeComponent /> is a PureComponent.

Avoid one frame delay

We need to measure the width of the container and hence need to wait before rendering some elements on the screen. If you know the initial width upfront, you can pass it in and we won't need to wait for measuring it. Most of the time, it's just the window width.

For example, pass the following initialLayout to TabView:

const initialLayout = {
  height: 0,
  width: Dimensions.get('window').width,
};

The tab view will still react to changes in the dimension and adjust accordingly to accommodate things like orientation change.

Optimize large number of routes

If you've a large number of routes, especially images, it can slow the animation down a lot. You can instead render a limited number of routes.

For example, do the following to render only 2 routes on each side:

renderScene = ({ route }) => {
  if (Math.abs(this.state.index - this.state.routes.indexOf(route)) > 2) {
    return <View />;
  }

  return <MySceneComponent route={route} />;
};

Contributing

While developing, you can run the example app to test your changes.

Make sure the tests still pass, and your code passes Flow and ESLint. Run the following to verify:

yarn test
yarn flow
yarn lint

To fix formatting errors, run the following:

yarn lint -- --fix

Remember to add tests for your change if possible.